A vehicle may include an engine control system for improving engine operation. The engine control system may be divided into several subsystems that may or may not be closely related. For example, an engine control system may include a fuel delivery system as well as an air charge estimation and regulation system. Further, the engine control system may also include an ignition system, fuel vapor management system, exhaust emissions system, an exhaust gas recirculation (EGR) system, valve timing system, and other such systems. The engine system, including each subsystem, may operate based on transfer functions that attempt to describe device operation as well as on open loop and closed loop commands. The open loop commands may be empirically determined during engine testing and stored in memory for use during selected operating conditions. The closed loop commands may be based on data that is collected and fed back to the engine system during vehicle operation.
The engine system may also adapt selected control parameters to compensate for errors that may be present in device transfer functions and/or open loop commands. In some examples, the control parameters may not be directly observable to determine whether or not the control parameters are converging to desired (e.g., optimal) values. Further, the control parameters may be adapted in response to present operating conditions without regard to prior operating conditions since the engine system has limited capacity to store vehicle data. For example, an engine system may include air and fuel management systems. The engine air amount may be estimated based on a manifold absolute pressure (MAP) sensor or air meter. The engine fuel amount may be estimated from fuel injection pulse widths. Correction to the air and fuel estimates may be based on output of an oxygen sensor that has no capacity to directly distinguish between air system errors and fuel systems errors. Consequently, air system control parameters and fuel system control parameters may be arbitrarily assigned portions of an air-fuel ratio error amount. Consequently, air system and fuel system corrections may not compensate for air system and fuel system errors as is desired.
The inventors herein have recognized the above-mentioned disadvantages and have developed a method for a vehicle, comprising: collecting data without driver input from a single source that is correlated to two regulated engine inputs while the vehicle is on a road; processing the data off-board the vehicle into control adjustments for the two regulated engine inputs; and operating the vehicle in response to the control adjustments.
By exporting vehicle data to an off-board processing system, it may be possible to improve adaptation of control parameters such as sensor and actuator transfer functions so that vehicle performance may be improved. For example, an engine exhaust gas oxygen sensor outputs data that may be related to an engine air charge control system and an engine fuel control system. Vehicle data including oxygen sensor data, air sensors, and fuel injection times may be organized into specific operationally separated data groups (e.g., engine starting data, engine stopping data, steady state data, and transient data) that are transmitted to a processing unit that is remote from the vehicle. The remote processing unit may process a large group of data that was acquired during varying operating conditions to adjust one or more sensor and/or actuator transfer functions based on the large group of data. The large group of data may allow the processing unit to determine if particular errors in the observed data may be attributed to either the fuel system or the air charge system. Fuel delivery system control variables are adjusted according to errors attributed to the fuel delivery system. Engine air charge system control variables are adjusted according to errors attributed to the engine air charge system.
The present description may provide several advantages. In particular, the approach may allow an engine to operate more efficiently. Further, the approach may reduce engine emissions. Further still, the approach may account for system errors that develop over a length of time.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.